Old stone



OLD STONE Filed Dec. 19, 1929 @M Mgg Patented Feb. 20, 1934 UNITED STATES OLD STONE Alvin A. Schmidt, Bensenville, lll.

Application December 19, 1929 Serial No. 415,258

4 Claims.

My invention relates in general to imitation old stone. It relates more in particular to an improved method of producing an articial stone finished in such a manner as to resemble an ancient art product or the like.

Certain styles of architecture and certain landscape eiIects call for the use of decorative stone articles, preferably stone articles having the appearance of great age. For example it may be desirable in keeping with a certainlandscape eifect to place an old or apparently old fountain in a certain position. This is just an example as there are hundreds of articles about a home which can be finished in antique stone in order to enhance the artistic effect. The production of articles of this kind, however, is fraught with many difficulties, and very skilled technique and good judgment must be used to obtain the proper artistic effect. Before my invention I have never seen a really successful antiquestone iinish. Accordingly the principal object of my invention in its inception was the production of an improved process for producing artificial stone.

Another object is the production of ornamental articles having the appearance of old stone.

The details of the invention Will be apparent from a consideration of the following description taken with the accompanying drawing which illustrates one type of article which may be taken as a sample of the work to which my invention applies.

The types of old stone are so numerous that it is a practical impossibility to give detailed instructions for the production of all types of stone. I shall refer to certain examples, however, of the application of the process which should be sufficient to enable those skilled in the art with a minimum amount of practice to copy all of the features of my invention.

No matter what the type of stone there are two distinct steps, namely the production of the article usually by casting, and secondly the finishing of the article to give it the proper color or weather stained effect.

First referring to the casting or production of the article itself this will vary depending upon the type of stone, for example I may produce what is known as a stained old Bedford stone, blue rock Bedford or other types of sand stone, and these may have a vermin appearance or may be without vermin depending upon a great many contingencies. Independent of the type of stone the iirst step is the production of (Cl. 41-10) i the molds. I prepare a mold suitable for casting the article desired, for example to produce the urn shown in the drawing a mold is produced which will hold the mixture in this position during setting. The Way in which the mold 'qu will be arranged of course will depend a very great deal on the character of the article being cast. That shown in the drawing could probably be cast in most instances by a simple three part mold.

In the first preparation of the mold the inside surface thereof is prepared to give the proper nish to the article. In usual practice the inside of a mold is treated with a relatively fine oil to produce an unusually smooth surface, and '(0 to prevent adherence between the mixture and -the inside of the mold. In preparing my mold where it is desirable to nish the article smooth I use a relatively thin oil. Where it is necessary to obtain a parted eiect I may employ a relau tively solid oil which can be put on warm and which becomes solid on cooling. This of course 'can be placed on in such a way asV to leave bumps, ridges and other types of irregularities which will cause the outside of the article to be g. parted and marked similar to an ancient stone article. Where unusual roughness is desired I may take a material such as tin foil and by crushing it up and sticking it against the inside of the mold further roughness is obtained in 8| the casting. I sometimes dust chalk entirely over the oil on the inside of the mold, and at other times I leave portions of the mold entirely unprotected by either oil or chalk so that it partially sticks to the casting and then a rough effect is'obtained in these places when the mold is removed. If in accordance with the design there would be a relatively large piece of the design broken away, as for example the edge of the urn as shown in the drawing, the inside of 9-5 the mold can be iinished to show this break.

The 'final nish of the casting determines almost entirely the mixture of substances which will go into the making thereof. In order to make this clear it might be stated that I obained the proper stained effect and weather marked effect principally by the use of metals which stain the outside of the casting. Now I may incorporate metals with the aggregate and then treat the finished casting to bring out the color of these metals to the extent desired or I may mix entirely without metals, which I find preferable, and then treat the surface of the castings only. I iind, however, that even Where no metals are employed in the aggregate the charworked out. cordance with this modification of the 'process is surface of the casting I generally employ* afmixture of pulverized sand stone and cement-of- I mayn proper kinds and in proper proportions. also use a iine silica sand or anyiinefsandfof a substantially white color which is adapted for receiving any type of stain desired; By ein# ploying a line grade of white silica sand,A white cement and finely crushed granite I hayeprol duced an artiiicial granite stone which could not'be distinguished-from'the natural granite. On the inside ofthe casting the aggregate is not so'important, and I may employ suitable lling material such as crushedl stone or the like, this depending upon the size of the casting,l its shape and requisite strength.

A usual effect on old stone is `that known as vermin, or,l with holes therein as if eaten by vermin. I-can secureV this effect in various ways,

3 depending upon the specific appearance desired:

The effect can be' obtained partly by simply roughening up the inside of the form, but the real effect is obtained, only by employing a dif- *l ferent-material in the aggregate', and alsoby i employing a so-called pre-cast aggregate.

First as tothe use of materials I may employ on the outside of the casting materials which may be dissolved by water, or by dilute acid solutions,

`)For example I may employ starch, clay or similar" materials in lump form which will afterward be washed out and leave an open space.

I obtain the best effect, however, by employing a pre-castl aggregate, that is I'prepare the aggregateas'if I were about to cast the article, mix' it with the requisite amount of cement, andfc'ast itin an open mold. When it has partiallyset I remove it from the mould and'break it up into pieces of relatively small size, and' ,w then store" it in a separate location marked withl sei-f the materials and proportions thereof contained init. When I am ready to make the castingI then prepare another aggregate of the same type and mix it with the same amount of cement alsookf' the same type, and when this isthor oughly mixed I'add the pre-cast aggregatel and then quickly place it in the mold in a wayso as to line' the inside thereof. The pre-cast aggregate" being in irregular lumps will cause n the'rformatio'n of cracks, etc. on thev outside of s the casting, and since the pre-cast aggregate has' exactly the samer composition as its binder a'unifo'rm colorI is obtained, and the Stain will eifect it in a uniform manner.

As previously noted the aggregate may include 5 metal particles. This is not the way I prefer to carry on my process but good results within certain limits are obtained thereby'particularly when following certain details which I have A sample of an aggregate in acthoroughly waxed, preferably by theuse of par-Y affin; stearic" acid or any oxidizable or' hydro- Vupon the result desired. 'Ihe specic manner of bringing out the color as already noted depends a very great deal on the previous history ofthe casting. When metal filings have been adde'dto the aggregate the surface of the casting is treatedY with various chemicals principally acids to"act'upon the metal particles, and upon the wax with which they are coated to bring out various colors resulting from the action on the metals, the colors being formed by combination-with oxygen',` sulphur, etc. Generally my rststepis'to wash the casting thoroughly with dilutel muriatic acid.` This cleans the outside of the casting, and at the same time starts chemical action on the surface thereof. I may treat certain portions of the casting with sulphuric acid or ammonia kor in certain cases clear rain water depending upon the colors I wish to obtain and the speed with which I wish to bring themout. the manner described above the use of ammonia will bring out a' combination green effect. The exact shades of colorsl and the like which are obtained with different combinations and different technique cannotbe explained in de- With an aggregate formed in extent upon his artistic conception of an original. The colors and shades, however, he can get by following my instructions.

As previously stated to obtain the best results Imix" the aggregate Without any metal, or at least with only such traces of metal as are found in'natural products and cement as well, but which in themselves are not present in proper form or in sufficient quantities to bring out an antique stone effect. I obtain my best results by forming liquid solutions of the proper materials which can be applied to the surface of the nish and green casting in accordance with theresult desired.

In'preparing the liquid solution I modify my process indifferent ways. For example where iron is used I may take a suitable source of iron such as iron lings, and the like and simply rust them by a natural process through exposure to water, weather, etc. until the iron has become' sufficiently oxidized to color the water a deep reddish brown color. I find that rain water is much better than any other type of water for use in this way. Or I may immerse the iron in sulphuric or muriatic or other acid and leave it'there until the entire acid content has affected the iron and a substantially neutral solutionV is formed. This will have various shades depending upon the acid type of iron and concentration thereof. So with copper and othermetals which I'might wish to use I imitc its

merse them in acids and leave them until the reaction has been completed to obtain color solutions of various kinds depending upon control of the conditions present. By using the various liquids produced in this way I am able toduplicate any stone color found in nature, provided of course that the best results are obtained by also controlling the material which goes into the casting. For example if I wish a light stone with a stained green effect over a portion of its surface, and a stained brownish red eiect over other portions of the surface, or a mottled combination of these two colors which sometimes occurs, it is obvious that I cannot obtain this result if in the production of the casting I employ a dark aggregate and a dark colored cement binder. In connection with treating the outside of the iinished casting I sometimes find it necessary to rub a pulverized metal compound directly into the surface of the casting. This may be any oxide, sulphate or the like, or in certain cases I may use a mixture of certain oxides with powdered graphite, or powdered graphite alone applied in certain ways.

One of the substances with which I have had unusually good results is the natural iron cre which is found between the various strata or rook and which has a reddish brown color with a slightly different appearance than any other iron product of natural manufacture. I take this substance and puiverize it after which I can either use it in the aggregate, or treat it to obtain a solution of its soluble constituents for treatment of the outside of the casting. For the purpose of illustrating one particular example oi my process I refer to the drawing. As shown this is in the form of an urn l, such as would be used for flowers or the like, and having a hollow interior 1l with a base 12. This is cast in a suitable mold from an aggregate consisting of finely sifted sand and pulverized lime stone with a light gray Portland cement as a binder. As shown the outside of the urn is provided with utes 13 and these would be formed by the mold. The vermin eiect is obtained by employing precast aggregate of sand stone and sand prepared in proper proportions as previously described. It will be noticed that there is a relatively large break at 14, such a break as this molded directly into the casting, but to bring out a feature such as this I would probably employ a hammer and simply break the piece out when the article has set sufficiently to be removed from the mold.

When the article is dried it is thoroughly cleaned and can then be stained to bring out to the maximum degree the effect of age. For example the portion of the urn facing the north may have a tinge of green, and the entire surface adjacent thereto and immediately surrounding the green may be colored to represent iron stains, etc. This is shaded out so that one side of the stone may simply be finished with a grayish blackish appearance.

What I claim as new and desire to protect by Letters Patent of the United States is:

1. The method of producing articial antique stone which comprises forming a suitable aggregate, casting the same with a suitable binder, breaking the pre-cast mass into relatively smaller pieces, forming a second aggregate including the pre-cast aggregate, casting the nal aggregate into a suitable mold with a suitable binder to produce a rotted or vermin eaten appearance on the exterior of the stone and staining the resulting casting with a solution of metal oxides, the oxide having a diierent eiect on the precast aggregate than on the material added in the second aggregate.

2. The method of producing an artificial stone of ant-ique appearance which comprises preparing an aggregate and casting it into a suitably shaped mold with a binder to produce an uneven vermin eaten effect on the exterior of the stone, and finally staining the cast article with suitable metal compounds to bring out the appearance of great age.

3. The method of producing an antique stone article, which comprises casting into a suitable mold, an aggregate having as a constituent thereof, a water soluble material capable of ben ing washed out of the article after it has set in the mold, removing the article from the mold, treating it to wash out the water soluble material near the surface so as to form a rough exterior having the physical appearance of rotted or vermin eaten stone, and finally staining the surface with metal oxide coloring matter to produce the color appearance of `old stone.

4. The method of producing a cast concrete body having the appearance or" old stone, which comprises forming a suitable aggregate, casting said aggregate with a suitable binder, breaking the cast aggregate into relatively smaller pieces, preparing a second aggregate having the same constituents and proportions as the first aggregate and including the pre-cast aggregate, and casting said nal aggregate to produce a product having the appearance of vermin eaten stone.

ALVIN A. SCHMIDT. 

